Line two baking sheets with foil; coat with cooking spray. In a large heavy saucepan, combine sugar, water, corn syrup and lemon juice. Bring to a boil over medium heat, about 5 minutes. Using a pastry brush dipped in water, wash down the side of the pan to eliminate sugar crystals.
Carefully stir in butter, one piece at a time. Cook until a candy thermometer reads 310° (hard-crack stage), stirring occasionally.
Remove from heat; stir in vanilla. Cool until slightly thickened, about 2-3 minutes. Coat a metal measuring tablespoon with cooking spray; drop caramel by tablespoonfuls onto prepared pans. (Reheat mixture over low heat if necessary). Immediately press a lollipop stick into the center of each.
Cool completely on prepared pans. Decorate as desired with melted chocolate. Refrigerate until set, about 10 minutes. Store between pieces of waxed paper in an airtight container.
Every editorial product is independently selected, though we may be compensated or receive an affiliate commission if you buy something through our links.